Known in the art is a composite stretchable member which has two sheets and a stretch part which is comprised of a plurality of elastic members which are arranged between these two sheets, in which composite stretchable member the two sheets are intermittently joined together in a stretch direction of the stretch part and a direction perpendicular to the stretch direction, the elastic members are arranged at the stretch part so as not to pass through the joined parts of the two sheets and are fastened to the two sheets at their two end parts, and each of the two sheets forms a plurality of pleats which extend continuously along the plurality of elastic members (see PTL 1).
Furthermore, PTL 1 shows such a composite stretchable member arranged at a waist opening part or waist side parts of a disposable diaper. Such a composite stretchable member can form a gather part (stretch part which has large number of pleats) with a soft feel at an absorbent product etc.